JPH0140347B

PURPOSE:To obtain a uniform two-color toner image on a recording paper, through the case of by decreasing the absolute value of the toner the polarity of toner charge of which is inverted than the absolute value of the specific charge of the other toner, and making alignment of toner specific charge after the pre-charge easy. CONSTITUTION:When a negative toner with smaller specific charge, e.g. -11muO/ g, than the conventional specific value of -18muO/g is used, the toner specific charge is around 22muO/g with the positive pre-charge and the value remarkably approaches the specific charge of the positive charge. If the specific charge of the negative toner is further smaller, although the specific charge of the positive and negative toners is further arranged, but the charge is